He began his fashion career working with his former wife Karin when in 1968 they were awarded all three first prizes in a design competition. Professionally he had been working as both a fashion illustrator and journalist and as a freelance designer for fashion houses in Italy, France and Germany. He is also well known in England.

Joop achieved international success in 1978, when he showed his fourth fur collection.

The label and company JOOP!, created in 1981, is recognised for its provocative collections as well as for its internationally award-winning fragrances.[citation needed] In early 1982 Joop showed his first prêt-à-porter women's collection, followed by his first men's collection in 1985. Two years later, with the launch of his first perfume collection, he made his name a trademark, with capital letters to symbolize energy along with an exclamation mark.[citation needed] Clothes, shoes, jewelry, eyeglasses and perfume were immediately available under this brand. The "JOOP!" label became available for licensing, and Joop's company no longer produced any of its own goods for sale. Since 1997, Joop's products have been sold through JOOP! GmbH with the exception of Parfum JOOP!, which was sold to Coty/Lancaster in 1991 followed by licensee contracts. In 1998 Wolfgang Joop sold 95% of his stake in the JOOP! GmbH to Wünsche AG and sold the remaining 5% in July 2001. This ended his involvement with JOOP!

In 2003, Wolfgang Joop founded WUNDERKIND, a high end, couture fashion label. He first presented WUNDERKIND with the Fall/Winter collection 2003 in Potsdam to an audience of press and retail guests. WUNDERKIND had its international debut in September 2004 when WUNDERKIND was invited by the CFDA to premier the collection at New York Fashion week before repositioning the label and moving to show in Paris in 2006.[2] Boutiques were opened in Berlin, London and Sylt.

In January 2011, it was reported that WUNDERKIND faced restructuring with the loss of staff. The Spring 2011 Paris show was cancelled.[3]

After over a year of inactivity to the outside world, on May 10, 2012 WUNDERKIND relaunched itself with a new fashion show in Potsdam. [5] A new general manager has been put in place and there are plans to open another store in Berlin and for steady but slower growth. [6]

Joop has diverse interests and is involved in many activities beyond fashion and design, including illustration. Over 100 of his works are on show at the Hamburger Museum für Kunst in Hamburg. Joop also collects art, particularly contemporary paintings and sculptures, as well as furniture.

Joop has written various books and many articles for newspapers and magazines, including Der Spiegel, Stern and Welt am Sonntag. His books include the gift book Das kleine Herz (2001), the cookbook Hectic Cuisine (2002), the autobiography Stillstand des Flüchtigen (2002) the novel Im Wolfspelz (2003) and Wolfgang Joop, Wunderkind.14467 Potsdam published by Rolf Heyne Collection (2009). He does not use a computer for his writing, instead preparing his manuscripts by hand.

Joop supports the Dunkelziffer e.V. organization for sexually abused children, and the Hamburg Leuchtfeuer organization for people with AIDS.